Nothing to do with curfew, it is always their procedure during a bad storm. They don't want folks wandering the property, possibly getting injured from falling trees or branches. They are not planning to keep anything open for you to visit so no reason to be outside. For guests safety and their liability.
Curfew is new, probably because Orlando never been hit like this. There will be emergency vehicles rolling, maybe power lines down, flooding and a big reason is sadly during storms looting occurs. The only way to protect the innocent and shut down the guilty is a curfew. With everything closed no reason to be out there, so be where you need to be by curfew deadline.